Composing life

Textbooks often assert that life began with specialized complex molecules, such as RNA, that are capable of making their own copies. This scenario has serious difficulties, but an alternative has remained elusive. Recent rese arch and computer simulations have suggested that the first steps toward li fe may not have involved biopolymers. Rather, noncovalent protocellular ass emblies, generated by catalyzed recruitment of diverse amphiphilic and hydr ophobic compounds, could have constituted the first systems capable of info rmation storage, inheritance and selection. A complex chain of evolutionary events, yet to be deciphered, could then have led to the common ancestors of today's free-living cells, and to the appearance of DNA, RNA and protein enzymes.